A suicide bomber killed five Israelis yesterday after he was spotted "walking like a robot" towards a shopping centre in the town of Netanya, the scene of an almost identical attack in July.

Shoppers alerted security guards and police, who surrounded the bomber before he triggered the explosives, carried in a bag. Around 40 people were injured in the blast, about 20 metres (65ft) from the spot where another five people died in July's attack. The bombing was the fifth this year and, like the previous attacks, it was carried out by Islamic Jihad.

Shoshi Attia, a policewoman, told Israel Radio: "I shouted for them to remove his hand from the bag and then the security guard caught him. I was looking him in the eye and he pressed [the button] and blew up. I flew and all I remember is that I was looking in his eye, I saw his gaze."

Karen Finkels, 31, a trainee lawyer, was walking on a bridge that links a court to the shopping centre. "I heard a loud bang but I didn't think it was a bomb until I looked down and saw all the glass panes broken and the stone wall of the shopping centre was damaged, the blast was so powerful. I was cut by flying glass but the worst thing was the shock," she said.

The bomber was identified as Lotfi Abu Saada, from the village of Illar, north of the West Bank town of Tulkarem. According to the Associated Press, relatives described the 23-year-old as a primary-school dropout who was illiterate and exploited by his handlers. "My son is a poor soul. He doesn't know anything about this," said his mother, Amina.

The Israeli army was ordered to launch reprisals against Islamic Jihad in the West Bank after meetings last night between the prime minister and security chiefs.

Some sections of Islamic Jihad claim to abide by the ceasefire that has been in place since February, but other members in the West Bank around Jenin and Tulkarem have continued bombing. Several have been killed in recent months in Israeli operations in the West Bank. In the last month Israeli troops have killed 15 Palestinians, including two children. One Israeli soldier was killed by Palestinians.

The day before the bombing, Dan Halutz, the Israeli chief of staff, told reporters that the army would continue to "run after Islamic Jihad". The barrier that Israel is building around the West Bank could never create a 100% guarantee of security, he added.

Israeli police said they were looking for a car that they believe dropped off the bomber in Netanya, which is only around 10 miles from the barrier that surrounds the West Bank town of Tulkarem.

The British ambassador to Israel, Simon McDonald, placed a wreath at the scene of the bombing yesterday on behalf of the European Union. Jack Straw, the British foreign minster, called the bombing a cowardly attempt to undermine progress in Israeli-Palestinian relations following the withdrawal from the Gaza Strip.

The bombing had an immediate effect on political debate within Israel, where elections are due in March. Shaul Mofaz, the defence minister fighting to become leader of the Likud party, called for a resumption of the policy of destroying the homes of suicide bombers' families.

Ariel Sharon, the prime minister, called together his security cabinet to discuss a response. Amir Peretz, the new Labour leader, called a meeting of his security advisers to ensure voters got the message that he could be tough on terrorism in spite of his reputation as a believer in reconciliation with the Palestinians.

Rightwing candidates such as Silvan Shalom, the foreign minister who is also fighting for the Likud leadership, blamed the Palestinian Authority for the attack. However the PA only has limited independence of action in the West Bank, where the Israeli army controls security.

The Palestinian president, Mahmoud Abbas, said in a statement: "This operation ... against civilians causes the most serious harm to our commitment to the peace process and the Palestinian Authority will not go easy on whoever is proved to be responsible."